The electrical wiring of large scale electronic equipment such as a computer usually involves a central wiring panel or backplane. The latter represents an interconnection medium of the printed wiring board type. Individual printing wiring boards containing the electronic components that comprise the active circuits are connected to the backplane. The latter is accomplished by providing connectors on the backplane in order that the printed wiring boards may be removed and replaced as desired. A well known method used to connect the connector contacts to the backplane is to press the connector contact pins into plated-through holes formed in the backplane. The plated material surrounding the holes is electrically connected to printed wiring leads or traces on or below the surface of the backplane. The connector contact pins are commonly of the compliant-type having a spring-like section that engages the walls of the plated-through hole, thereby providing solderless electrical connection to the backplane.
Situations often exist in electronic design where a circuit change requiring disconnection of electrical paths and rewiring are to be included into the completed equipment. Obviously, it is advantageous to make the required circuit changes without revising the backplane printed wiring board. In the referenced copending application, a change pin having a unitary body member and an insulative sleeve disposed about a substantially medial portion thereof is inserted into a plated-through hole to effectively insolate the printed wiring associated with the latter. As noted in the application, the change pin is retained in the board by a press fit action. Also, it was noted that a family of change pins may be required to function over the tolerance range of the back plane via holes. The circuit change procedure, in this case would involve removing the original compliant pin and gauging the hole with a plug gauge. Then, the proper insulated change pin could be selected and press fitted into the hole.
While the above procedure represents a practical and workable solution to the circuit change problem, it is desirable to have a single wiring change pin of such a design that is universal, easy to install, and tolerance-free as to the dimensions of the circuit board plated-through holes. The change pin of the present invention fills such a need.